Vehicle seat

ABSTRACT

A vehicle seat is provided comprising a seat back frame having right and left side frames, a headrest for supporting a head of a seat occupant, and a back-and-forth movable plate member provided inside a backrest that is positioned at a rear of the seat occupant, wherein a backward movement of the plate reduces a distance between the head of the seat occupant and the headrest. The plate is attached to each side frame through a link member and a link support shaft swingably supports the link member. A bracket member that supports the link support shaft and is attached to the side frame.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 13/361,142, filed Jan. 30, 2012, which is a divisionalapplication of U.S. patent application Ser. No. 13/077,325, filed Mar.31, 2011, which is a divisional application of U.S. patent applicationSer. No. 12/279,766, filed Jun. 18, 2009, which is a PCT national stageentry of international patent application no. PCT/JP2005/13468, filedJul. 22, 2005. The contents of these applications are hereinincorporated by reference.

BACKGROUND

The present invention relates to a coupling mechanism for a headrest ofa vehicle seat, and more particularly to a coupling mechanism for movingthe headrest forward when a forward external force acts on a car body asa result of rear end collisions or the like.

Conventionally, there is known from Japanese Patent ApplicationLaid-Open No. 10-119619 a vehicle seat having a headrest provided in abackrest, a movable member provided inside of the backrest, and acoupling mechanism for coupling the headrest and the movable membermechanically, in which, when a vehicle seat occupant moves backwardrelative to the vehicle seat due to rear collisions or the like, themovable member is pushed by the occupant to move backward, and thebackward movement of the movable member moves the headrest forward byway of the coupling mechanism.

The coupling mechanism of the prior art is disposed substantially at thebackside of a cushion of the backrest, and thus the cushion performancemay be lowered. That is, the coupling mechanism is provided at aposition overlapping the vehicle seat occupant in the front-to-backdirection, and thus the cushion design is restricted.

The movable member in the prior art is narrow in its movable range, andthe distance of moving the headrest forward is short, and means forcompensating for lack of distance is difficult.

SUMMARY

It is hence an object of embodiments of the invention to provide acoupling mechanism for a headrest capable of amplifying the small movingamount of the movable member and transmitting the movement to theheadrest. It is another object of embodiments of the invention toprovide a coupling mechanism for a headrest capable of amplifying themoving amount of the movable member with a simple configuration. It isstill another object of the invention to provide a coupling mechanismfor a headrest not interfering with the cushion of the backrestsubstantially.

Therefore, a vehicle seat is provided comprising a seat back framehaving right and left side frames, a headrest for supporting a head of aseat occupant, and a back-and-forth movable body provided inside abackrest that is positioned at a rear of the seat occupant, wherein abackward movement of the back-and-forth movable body forwardly moves theheadrest to support the head of the seat occupant. The back-and-forthmovable body is attached to each side frame through a link member and isprovided with a backward protrusion protruding backward, and thebackward protrusion extends laterally.

A vehicle seat is also provided comprising a seat back frame havingright and left side frames, a headrest for supporting a head of a seatoccupant, and a back-and-forth movable body provided inside a backrestthat is positioned at a rear of the seat occupant, wherein a backwardmovement of the back-and-forth movable body forwardly moves the headrestto support the head of the seat occupant. The back-and-forth movablebody is attached to each side frame through a link member and isprovided with a backward protrusion protruding backward in at least anend part in a vertical direction, and the backward protrusion extendslaterally.

A vehicle seat is also provided comprising a seat back frame havingright and left side frames, a headrest for supporting a head of a seatoccupant, and a back-and-forth movable body provided inside a backrestthat is positioned at a rear of the seat occupant, wherein a backwardmovement of the back-and-forth movable body forwardly moves the headrestto support the head of the seat occupant. The back-and-forth movablebody is attached to each side frame through a link member and isprovided with first and second backward protrusions protruding backward,and the first and second backward protrusions extend laterally and arearranged in parallel with each other.

A vehicle seat is also provided comprising a seat back frame havingright and left side frames, a headrest for supporting a head of a seatoccupant, and a back-and-forth movable body provided inside a backrestthat is positioned at a rear of the seat occupant, wherein a backwardmovement of the back-and-forth movable body forwardly moves the headrestto support the head of the seat occupant. The back-and-forth movablebody is attached to each side frame through a link member, provided witha first backward protrusion protruding backward in an upper end partthereof, and provided with a second backward protrusion protrudingbackward in a lower end part thereof, and the first and second backwardprotrusions extend laterally.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is shown in the following figures.

FIG. 1 is an overall perspective view of a vehicle seat;

FIG. 2 is a perspective view showing a backrest frame and a part of acoupling mechanism for a headrest;

FIG. 3 is a side view of the coupling mechanism for a headrest;

FIG. 4 is a front view of the backrest frame and the coupling mechanismfor a headrest;

FIG. 5 is a magnified side view of a lower link mechanism of thecoupling mechanism;

FIG. 6 is a sectional view of a first link of the coupling mechanism;

FIG. 7 is a magnified side view of an upper link mechanism of thecoupling mechanism; and

FIG. 8 is a magnified side view showing the first link elevated from thestate in FIG. 7.

DETAILED DESCRIPTION

An embodiment of the invention will be described with reference to theaccompanying drawings. A vehicle seat 1 of the invention has a backrest2A, a seat bottom 2B, and a headrest 3 having a head support 4 isprovided in an upper part of the backrest 2A. A backrest frame 16 of thebackrest 2A has a square frame shape, including a pair of side frames40, each having an inward extension 40 a and outwardly recessed portion50, an upper frame 41, and a lower frame 42.

Near the upper frame 41, an upper movable member 10 (headrest supportmember) movable laterally to the backrest frame 16 is disposed. Verticalpillar supports 11 for inserting the lower parts of pillars 6 of theheadrest 3 are fixed in the movable member 10. The pillars 6 aresupported by the pillar supports 11 to be adjustable in height. Themovable member 10 also has an outward extension 12 a, and a forwardextension 12 b, as well as a protrusion 14 having an anteroposteriorextension, and a forward bent portion 14 a.

Both right and left sides of the upper movable member 10 are attached tothe backrest frame 16 by way of an individual upper link mechanism 15.Each upper link mechanism 15 has a long first link 17 (downwardextension, lateral portion of headrest support member), an arm 18(second link member), and a second link 23 (first link member) as shownin FIGS. 2, 3 and 7. The end part of the upper movable member 10 isfixed to an upper part of the first link 17, and the arm 18 is rotatablypivoted on an L-shaped bracket 20 (or a bracket, bracket member, orupper bracket), having upper 20 a and lower 20 b fixing portions, fixedin the upper part of the backrest frame 16 by way of a shaft 21 (secondlink support shaft), and having a link support portion 20 c. Anintersection 13 exists between the first link 17 and the forwardextension 12 b. The second link 23 is rotatably pivoted on the bracket20 by way of a shaft 25 (first link support shaft). The leading end ofthe arm 18 is pivoted on the vertical intermediate position of the firstlink 17 by way of a shaft 19 (second coupling shaft), and the leadingend of the second link 23 is pivoted on the lower part of the first link17 by way of a shaft 24 (first coupling shaft). The other end of thesecond link 23 is pivoted on the upper part of a long coupling rod 27(transmission member) by way of a shaft 28. The bracket 20 has a linksupport portion 51 with a link support surface 52. The second link 23has a bracket attachment 53, a first extension 54 and a second extension55. The second link 23 also has a bent portion 56.

The first link 17, the arm 18 and the second link 23 of the upper linkmechanism 15 are preliminarily assembled in, preferably, the bracket 20.As a result, the bracket provided with the link mechanism can be easilyassembled in the backrest frame 16 as a unit module. The bracketprovided with the link mechanism makes it easy to manage storage parts,and to replace parts in maintenance operations.

As shown in FIGS. 2 and 6, one end of an upper spring 29 is coupled tothe lower part of the first link 17, and the other end of the upperspring 29 is coupled to the side frame 40. The first link 17 is usuallyheld at a lower waiting position in FIG. 7 by an elastic force of thespring 29, and hence the headrest 3 is held at an ordinary position.When the first link 17 moves up to a position indicated by solid line inFIG. 8, the upper movable member 10 moves forward, and the headrest 3 isforced out forward.

Between the side frames 40, 40, a lower movable member 30 (a movableplate member), which may be a back-and-forth movable body or a sensingmember, stretching laterally is disposed. The lower movable member 30 ispushed by a vehicle seat occupant and moved backward when the vehicleseat relatively moves forward of the occupant due to a rear endcollision. Both sides of the lower movable member 30 are coupled to theends of the lower link 31 (link member) of the lower link mechanism 32by way of shafts 38 (coupling shafts). The lower movable member 30comprises a plate-shaped portion 30 e that connects to the shaft 38 viaa coupling plate member 30 a (also called a coupling member or endextension) through a first (or first forward) extension 30 a 1, second(or outward) extension 30 a 2, and third (or anteroposterior) extension30 a 3 (or forward extending portion). The forward extending portion 30a 3 comprises a front bent portion 30 a 3.1 that is formed at its frontend. The forward extension 30 a 1 comprises an elongated (or through)hole 30 a 4. The lower movable member 30 also comprises a shaft member30 g. The other end of the lower link 31 is coupled to the lower part ofthe coupling rod 27 (transmission member) by way of a shaft 37. Thelower link 31 is preferably a bell crank. The center of the lower link31 is pivoted on a lower bracket 35 (bracket member), having upper (orfirst) 35 a and lower (or second) 35 b fixing portions, fixed to theside frame 40 by way of a shaft 36 (link support shaft). The bracketmember may also have an inward protruding surface 35 c, a front fixingportion (or first attachment portion) 35 d, and a rear fixing portion(or second attachment portion) 35 e.

As shown in FIG. 2, one end of the lower spring 39 is coupled to thelower movable member 30, and the other end of the lower spring 39 iscoupled to the side frame 40. The lower movable member 30 is held at aforward ordinary position by the elastic force of the spring 39, andwhen a rear end collision occurs, it is pushed by the vehicle seatoccupant and moved backward by resisting the elastic force of the spring39.

In FIGS. 3 and 5, the backward movement of the lower movable member 30causes the lower link 31 to rotate counterclockwise about the shaft 36,and causes the coupling rod 27 to be pulled downward. As a result, thesecond link 23 rotates counterclockwise about the shaft 25, and movesthe first link 17 upward by resisting the elastic force of the upperspring 29. At this time, the distance between the shaft 25 and shaft 28is shorter than the distance between the shaft 25 and shaft 24. Thus,the second link 23 amplifies the moving amount of the coupling rod 27(lower movable member 30) to transmit the movement to the first link 17,the upper part of the first link 17 is guided by the arm 18 and movedsubstantially forward as shown in FIG. 8, and thereby the headrest 3 ismoved forward by way of the upper movable member 10 so that a cervicalspine of the vehicle seat occupant is protected in the event of a rearend collision.

Thus, the upper link mechanism 15 of this embodiment of the inventionhas a function of moving the headrest 3 largely forward with a smallmoving amount of the lower movable member 30. The lower movable member30 comprises backward protrusions 30 f. The backward protrusions 30 fmay comprise a first backward protrusion 30 b (upper backwardprotrusion, first turn-back portion) and a second backward protrusion 30c (lower backward protrusion, second turn-back portion). These each maycomprise a first (or backward) bent portion 30 d 1 and a second (orforward) bent portion 30 d 2.

The side frame 40 of the backrest frame 16 is formed of a metal platehaving a specified width in the front-to-back direction, and the upperlink mechanism 15, coupling rod 27, and lower link 31 are disposedadjacent to the side frame 40. In addition, the members of the upperlink mechanism 15 and the lower link 31 are formed of platessubstantially parallel to the side frame 40, and are supported by theshaft in the lateral direction. The upper movable member 10substantially overlaps with the upper frame 41 of the backrest frame 16.Therefore, the mechanism for transmitting the movement of the lowermovable member 30 to the headrest 3 does not substantially interferewith the cushion 5 of the backrest 2A. Hence, the transmission mechanismis operated smoothly, and decline of performance of the cushion 5 isprevented.

TABLE OF REFERENCE CHARACTERS

-   1 vehicle seat-   2A backrest-   2B seat bottom-   3 headrest-   4 head support-   5 cushion-   6 pillars-   10 upper movable member; headrest support member-   11 pillar supports-   12 a outward extension-   12 b forward extension-   13 intersection-   14 protrusion-   14 a anteroposterior extension; forward bent portion-   15 upper link mechanism-   16 backrest frame-   17 long first link; downward extension; lateral portion of headrest    support member-   18 arm; second link member-   19 shaft; second coupling shaft-   20 L-shaped bracket; bracket; bracket member; upper bracket-   20 a,b upper and lower fixing portions of bracket member-   20 c bracket member link support portion-   21 shaft; second link support shaft-   23 second link; first link member-   24 shaft; first coupling shaft-   25 shaft; first link support shaft-   27 long coupling rod; transmission member-   28 shaft-   29 upper spring-   30 lower movable member; back-and-forth movable body; sensing    member; movable plate member-   30 a coupling plate member; coupling member; end extension-   30 a 1 first extension; forward extension-   30 a 2 second extension; outward extension-   30 a 3 third extension; anteroposterior extension; forward extending    portion-   30 a 3.1 front bent portion-   30 a 4 forward extension elongated hole; through hole-   30 b first backward protrusion; upper backward protrusion; first    turn-back portion-   30 c second backward protrusion; lower backward protrusion; second    turn-back portion-   30 d 1 first bent portion; backward bent portion-   30 d 2 second bent portion; forward bend portion-   30 e plate shaped portion-   30 f backward protrusion-   30 g shaft member-   31 lower link; bell crank; link member-   32 lower link mechanism-   25 lower bracket; bracket member-   35 a upper fixing portion of bracket member; first fixing portion of    bracket member-   35 b lower fixing portion of bracket member; second fixing portion    of bracket member-   35 c inward protruding surface of bracket member-   35 d front fixing portion of bracket member; first attachment    portion of bracket member-   35 e rear fixing portion of bracket member; second attachment    portion of bracket member-   36 shaft; link support shaft-   37 shaft-   38 shaft; coupling shaft-   39 spring-   40 side frame-   40 a inward extension-   41 upper frame-   42 lower frame-   50 outwardly recessed portion-   51 link support portion-   52 link support surface-   53 bracket attachment-   54 first extension-   55 second extension-   56 bent portion

What is claimed is:
 1. A vehicle seat comprising: a side frameconstituting a backrest; a headrest for supporting a head of a seatoccupant; a movable plate member that is provided inside the backrestand disposed at a rear of the seat occupant, and is movable backward inresponse to a load from the seat occupant, wherein a backward movementof the movable plate member reduces a distance between the head of theseat occupant and the headrest; the movable plate member is connected tothe side frame via a link member; a link member that attaches themovable plate member to the side frame therethrough; a link supportshaft that swingably supports the link member; and a bracket member thatsupports the link support shaft and is attached to the side frame;wherein: at least a part of the movable plate member and the bracketmember are disposed in a first horizontal plane; the movable platemember is provided with a through-hole; and at least a part of thebracket member and the through-hole are disposed in a second horizontalplane.
 2. The vehicle seat according to claim 1, wherein at least a partof the through-hole is disposed below an upper end of the bracketmember.
 3. The vehicle seat according to claim 1, wherein at least apart of the through-hole is disposed below the link support shaft. 4.The vehicle seat according to claim 1, wherein: each of right and leftend portions of the movable plate member is connected to a respectivelower end portion of the link member via a coupling shaft; and at leasta part of the through-hole is disposed below a third horizontal planepassing through a shaft center of the link support shaft and above afourth horizontal plane passing through a lower end of the link member.5. The vehicle seat according to claim 1, wherein: each of right andleft end portions of the movable plate member is connected to arespective lower end portion of the link member via a coupling shaft;and at least a part of the through-hole is disposed below a thirdhorizontal plane passing through a shaft center of the link supportshaft and above a fifth horizontal plane passing through a shaft centerof the coupling shaft.
 6. The vehicle seat according to claim 1, whereinthe through-hole is of an elongate form.
 7. The vehicle seat accordingto claim 1, wherein the through-hole is of an elongate form elongated inan up-to-down direction.
 8. A vehicle seat comprising: a side frameconstituting a backrest; a headrest for supporting a head of a seatoccupant; a movable plate member that is provided inside the backrestand disposed at a rear of the seat occupant, and is movable backward inresponse to a load from the seat occupant, wherein a backward movementof the movable plate member reduces a distance between the head of theseat occupant and the headrest; the movable plate member is connected tothe side frame via a link member; a link member that attaches themovable plate member to the side frame therethrough; a link supportshaft that swingably supports the link member; and a bracket member thatsupports the link support shaft and is attached to the side frame;wherein: at least a part of the movable plate member and the bracketmember are disposed in a first horizontal plane; each of right and leftend portions of the movable plate member is provided with a respectiveforward extending portion that extends forward; each of the forwardextending portions is provided with a through-hole; and at least a partof the bracket members and the through-holes are disposed in a secondhorizontal plane.
 9. The vehicle seat according to claim 8, wherein atleast a part of each of the through-holes is disposed below an upper endof the bracket member.
 10. The vehicle seat according to claim 8,wherein at least a part of each of the through-holes is disposed belowthe link support shaft.
 11. The vehicle seat according to claim 8,wherein the through-holes are of an elongate form.
 12. The vehicle seataccording to claim 8, wherein each of the through-holes is of anelongate form elongated in an up-to-down direction.
 13. The vehicle seataccording to claim 8, wherein: a front portion of each of the forwardextending portions is connected to a lower end portion of the respectivelink member via a respective coupling shaft; and at least a part of eachof the through-holes is disposed below a third horizontal plane passingthrough a shaft center of the link support shafts and above a fourthhorizontal plane passing through a lower end of the link members. 14.The vehicle seat according to claim 8, wherein: a front portion of eachof the forward extending portions is connected to a lower end portion ofthe respective link member via a respective coupling shaft; and at leasta part of the through-holes is disposed below a third horizontal planepassing through a shaft center of the link support shafts and above afifth horizontal plane passing through a shaft center of the couplingshafts.
 15. The vehicle seat according to claim 8, wherein: each of theforward extending portion is connected to a respective lower end portionof the link member via a respective coupling shaft; and a rear end ofthe through-holes is disposed posterior to the coupling shafts.
 16. Thevehicle seat according to claim 8, wherein: a front bent portion isformed at a front end of each of the forward extending portions; and thefront bent portions and the through-holes are disposed in a sixthhorizontal plane.
 17. A vehicle seat comprising: a side frameconstituting a backrest; a headrest for supporting a head of a seatoccupant; a movable plate member that is provided inside the backrestand disposed at a rear of the seat occupant, and is movable backward inresponse to a load from the seat occupant, wherein a backward movementof the movable plate member reduces a distance between the head of theseat occupant and the headrest; the movable plate member is connected tothe side frame via a link member; a link member that attaches themovable plate member to the side frame therethrough; a link supportshaft that swingably supports the link member; and a bracket member thatsupports the link support shaft and is attached to the side frame;wherein: at least a part of the movable plate member and the bracketmember are disposed in a first horizontal plane; the movable platemember is provided with a through-hole; a first turn-back portion isprovided at an upper end of the movable plate member; a second turn-backportion is provided at a lower end of the movable plate member; thethrough-hole is disposed below a seventh horizontal plane passingthrough the first turn-back portion and above an eighth horizontal planepassing through the second turn-back portion; and at least a part of thebracket member and the through-hole are disposed in a second horizontalplane.
 18. The vehicle seat according to claim 17, wherein at least apart of the through-hole is disposed below an upper end of the bracketmember.
 19. The vehicle seat according to claim 17, wherein at least apart of the through-hole is disposed below the link support shaft. 20.The vehicle seat according to claim 17, wherein: each of right and leftend portions of the movable plate member is connected to a respectivelower end portion of the link member via a respective coupling shaft;and at least a part of the through-hole is disposed below a thirdhorizontal plane passing through a shaft center of the link supportshaft and above a forth horizontal plane passing through a lower end ofthe link member.
 21. The vehicle seat according to claim 17, wherein:each of right and left end portions of the movable plate member isconnected to a respective lower end portion of the link member via arespective coupling shaft; and at least a part of the through-hole isdisposed below a third horizontal plane passing through a shaft centerof the link support shaft and above a fifth horizontal plane passingthrough a shaft center of the coupling shaft.
 22. The vehicle seataccording to claim 17, wherein the through-hole is of an elongate form.23. The vehicle seat according to claim 17, wherein the through-hole isof an elongate form elongated in an up-to-down direction.
 24. Thevehicle seat according to claim 17, wherein the first turn-back portioncomprises a backward bent portion that is bent backward and a forwardbent portion that is bent forward.
 25. The vehicle seat according toclaim 24, wherein the backward bent portion and the forward bent portionare continuously formed.
 26. The vehicle seat according to claim 25,wherein the backward bent portion, the forward bent portion and thesecond turn-back portion are disposed in a same vertical plane.
 27. Thevehicle seat according to claim 17, wherein the through-hole and afixing portion by which the bracket member is attached to the side frameare disposed in a ninth horizontal plane.
 28. The vehicle seat accordingto claim 17, wherein: the bracket member is fixed to the side frame byan upper fixing portion and a lower fixing portion; and the lower fixingportion and the through-hole are disposed in a ninth horizontal plane.29. The vehicle seat according to claim 24, wherein the through-hole isdisposed below the backward bent portion and the forward bent portion,and above a lower end of the bracket member.
 30. The vehicle seataccording to claim 8, wherein: the bracket member is fixed to the sideframe by an upper fixing portion and a lower fixing portion; and atleast a part of the forward extending portion and the bracket member aredisposed in a tenth horizontal plane at a position below the upperfixing portion and above the lower fixing portion.
 31. The vehicle seataccording to claim 1, wherein the through-hole and the bracket memberare disposed in an overlapped manner in a right-to-left direction. 32.The vehicle seat according to claim 8, wherein the through-hole and thebracket member are disposed in an overlapped manner in a right-to-leftdirection.
 33. The vehicle seat according to claim 17, wherein thethrough-hole and the bracket member are disposed in an overlapped mannerin a right-to-left direction.
 34. The vehicle seat according to claim 1,wherein the through-hole and at least a part of a fixing portion bywhich the bracket member is attached to the side frame are disposed inan overlapped manner in a right-to-left direction.
 35. The vehicle seataccording to claim 8, wherein the through-hole and at least a part of afixing portion by which the bracket member is attached to the side frameare disposed in an overlapped manner in a right-to-left direction. 36.The vehicle seat according to claim 17, wherein the through-hole and atleast a part of a fixing portion by which the bracket member is attachedto the side frame are disposed in an overlapped manner in aright-to-left direction.